The invention relates to a bi-directional communication data transaction card with an onboard processor for effecting both xe2x80x9ccontactxe2x80x9d and xe2x80x9ccontactlessxe2x80x9d modes of data transfer.
Both xe2x80x9ccontactxe2x80x9d and xe2x80x9ccontactlessxe2x80x9d bi-directional communication data transaction cards are known per se. A concise introduction to the nomenclature and principal features of data transaction cards, also called data cards or smart cards, is found in an IEEE Conference Paper by Klaus Vedder, The Hague, May 4-8, 1992, hereinafter referred to as Vedder. Another general overview is given by Gilles Lisimaque in a paper called xe2x80x9cSmart Cardsxe2x80x9d delivered at the 27th. International SAMPE Technical Conference, Oct. 9-12, 1995. Smart cards represent a specific implementation of chip cards wherein the chip is a microcomputer having a programmable memory.
Generally, such smart cards are provided either with electrical contacts for effecting direct electrical contact with a card reader, or with an antenna coil for effecting contactless bi-directional communication with a remote card reader. U.S. Pat. No. 5,206,495 for a Chip Card in the name of H. D. Kreft discloses a chip card allowing both contact and contactless communication in a single smart card.
A principal object of U.S. Pat. No. 5,206,495 is the provision of a chip card including both a contact field and transmission coils and a switching element device coupled between both and a semiconductor device such as a microcomputer.
International Patent Publication No. WO 98/29830, in the name of the present applicant, discloses a contact/contactless data transaction card which automatically conforms to a required communication mode in accordance with whether data is received via the antenna or via the contacts.
Contactless smart cards are particularly suited for applications, such as mass transport systems, wherein data communication must be effected very quickly without imposing the overhead incurred in manually introducing the smart card into the slot of a card reader.
Common to all such smart cards is an on-board microcomputer including a memory and processing capability for effecting the desired bi-directional data transmission and data storage. In the case where xe2x80x9ccontactxe2x80x9d data transmission is required, there is provided a so-called xe2x80x9ccontact fieldxe2x80x9d having a plurality of contacts, each of which is connected to the microcomputer by means of a respective electrical connection. Data transmission with an external reader is then effected by inserting the card into a suitable reader having a spring-loaded contacts which bear on the respective contacts in the contact field of the chip card.
Alternatively, when contactless data transmission is required, an antenna coil in the chip card is adapted to receive data from and transmit data to a reading device having a similar antenna.
Sometimes, such contact/contactless cards are called hybrid cards. These cards are thus packaged, with at least, components such as contacts, a microcomputer and an antenna.
As smart cards are presently mass-produced by the hundreds of millions, the assembly of the components and their embedding and packaging into the cards must be performed by fast and cost-effective processes. For purposes of compatibility, international standards govern the smart card industry. Thus, the dimensions and the location of the contacts of smart cards are laid down by Part 2 of the International Standard ISO 7816. The card itself, known as xe2x80x9cstandard identification cardxe2x80x9d or xe2x80x9cID-1 cardxe2x80x9d, is the size of a regular credit card. The thickness of the card is approximately 0.8 mm.
The ISO 7816 standard defines eight contacts, in two columns of four, but typically, only five or six are put to use. The other two or three are reserved for future utilization and therefore often not provided. Each single contact measures at least 2xc3x971.7 mm. The eight contacts of the contact field are contained in a square of about 10xc3x9710 mm, thus covering an area of about 1 cm2. FIG. 1a provides the minimum dimensions of the contacts, their arrangement and their location in the upper left corner of a card, as dictated by the ISO 7816. standard. FIG. 1b gives an example of a contact field with an eight contact layout. The microcomputer or integrated circuit used in a data transaction card is usually integrated on to a single piece of silicon. The size of a chip generally only extends from some 1 mm2 to 16 mm2, with a thickness ranging from 0.1 to 0.2 mm.
Typically, the antenna coil is wound around the periphery of the card, thus having dimensions approximately equal to those of the card and being very much greater than those of the contact field. As a result, the contacts induce no deleterious effect on the operability of the antenna coil. This, however, is not the case when the antenna coil is reduced in size so as to allow for its mounting directly on the integrated circuit. In such case, the close proximity of the mass of metal constituted by the contact field to the antenna coil, can interfere with its operability.
Different designs have been devised for the assembly of the many components of a smart card into a finished product. For example, U.S. Pat. No. 5,589,032 in the name of J-C. Fidalgo provides a bi-directional contact and contactless communication card. Fidalgo describes all the necessary components and suggests ways to facilitate their assembly, their electrical connection and their final integration. Nevertheless, the assembly still requires the laborious addition of components both in the body of the card 2, as well as in the electronic module 7. For example, the antenna 5 is embedded in the body of the card 2 and must be connected to the chip 8 which is itself part of the electronic module 7. Thus the different discrete components must be electrically interconnected. Thus, the card described by Fidalgo is not based on modular building blocks which are amenable for mass assembly.
To alleviate the difficulties encountered with the assembly and connection of the antenna, German Patent No. 37 21 822, in the name of K. Sickert, proposes forming the coil antenna 4 on to the semiconductor of the Integrated Circuit 5, around the active surface of the semiconductor and along its borders. Such a scheme allows the antenna to be provided during the manufacture of the integrated circuit and thus obviates the need electrically to connect the antenna to the integrated circuit in an independent subsequent stage of assembly. However, Sickert limits his invention to the antenna-chip pair and does not deal with further components. Also, since the size of the antenna is necessary limited by the dimensions of the semiconductor wafer, the transmission range is short.
In International Patent Publication No. WO 96/35190, to Reiner, there is suggested a method for contactless inductive coupling of a small antenna to a larger one. As an improvement upon Sickert, a small antenna, along the edges of a substrate, is inductively coupled to a larger antenna, disposed along the edges of the card itself.
It is an object of the invention to provide a data transaction card constructed by assembly of the body of a card with a chip carrier module.
It is a further object of the invention to provide such a data card wherein all the electronic components reside in the chip carrier module, so that no additional electrical connections are required between the coil antenna and the chip carrier module.
In accordance with a broad aspect of the invention there is provided a data transaction card having an interface for bi-directional contactless communication, the data transaction card comprising:
a support having a cavity for accommodating therein a chip carrier module which comprises:
a substrate having a first side and a second side,
an integrated circuit mounted on the first side of the substrate for managing functions of the data transaction card, and
a coil antenna electrically connected to the integrated circuit for inductive coupling with a remote antenna, connections to the coil antenna being accessible from the first side of the substrate;
the chip carrier module being packaged into one discrete unit so as to be amenable to mechanical assembly of the data transaction card without requiring additional electrical connections between the coil antenna and the chip carrier module during or subsequent to assembly.
Preferably, the chip carrier module hosts an optical visual authentication mark, such as an encoded hologram, formed into a personalized identification mark by insertion of a picture of the bearer of the card as the encoded hologram.
Preferably, the contact/contactless data transaction card further comprises a contact field for contact communication, wherein the card and the contacts are compatible with the 1S0 7816 Standard for contact cards. The contact field includes separate contacts applied on the second side of the substrate, for contact communication between the data transaction card and a card reader.
Preferably, the contact/contactless data transaction card is assembled by use of the conventional methods employed for the production of contact data cards.
In accordance with a preferred embodiment, the antenna comprises more than one winding applied either on the first or second side of the substrate. Alternatively, two antennae may be provided each on an opposite side of the substrate and having the same or a different number of windings. In such case, the two antennae behave as a parallel plate capacitor whose capacitance may be exploited to adjust an operational frequency of a tuned circuit containing the coil antennae. If desired, such tuning may be realized by an external capacitor coupled to the substrate.
Furthermore, it is also preferable for the windings of the coil antenna to be applied along the periphery of the substrate.
The invention also contemplates a method for manufacturing a data transaction card, method comprising the steps of:
(a) providing a support having a cavity therein,
(b) independently producing a chip carrier module having embedded therein an integrated circuit and a coil antenna electrically connected to said integrated circuit without requiring additional electrical connections between the coil antenna and the chip carrier module during or subsequent to assembly without requiring additional electrical connections between the coil antenna and the chip carrier module during or subsequent to assembly, and
(c) mounting the chip carrier module in the cavity of the support.